A freight train has a mass of 1.4 107 kg. If the locomotive can exert a constant pull of 8.1 105 N, how long does it take to increase the speed of the train from rest to 66 km/h?

Answer 1

F = = ma,
a = F/m = 8.1*10^5 / 1.4*10^7 = 0.058m/s^2.

Vf = 66km/h * 1000m/km * (1/3600)h/s =
18.33m/s.

t = (Vf - Vo) / a,
t = (18.33 - 0) / 0.058 = 316s.

Answer 2

124.2 s